So Luke Skywalkers dad:
Had over 20,000 midichlorians:
To the best of my knowledge, the specific number of midi-chlorians that Luke possesses has not been stated in current Disney canon. That said, some interviews with George Lucas can shed some limited light on the matter.
According to an interview with George Lucas in Rolling Stone.
You got it. And when he finds out Luke is his son, his first impulse is to figure out a way of getting him to join him to kill the Emperor. That’s what Siths do! He tries it with anybody he thinks might be more powerful, which is what the Emperor was looking for in the first place: somebody who would be more powerful than he was and could help him rule the universe. But Obi-Wan screwed that up by cutting off his arms and legs and burning him up. From then on, he wasn’t as strong as the Emperor – he was like Darth Maul or Count Dooku. He wasn’t what he was supposed to become. But the son could become that.
And, perhaps even more clearly:
“Anakin, as Skywalker, as a human being, was going to be extremely powerful,” he says. “But he ended up losing his arms and a leg and became partly a robot. So a lot of his ability to use the Force, a lot of his powers, are curbed at this point, because, as a living form, there’s not that much of him left. So his ability to be twice as good as the Emperor disappeared, and now he’s maybe 20 percent less than the Emperor. So that isn’t what the Emperor had in mind. He wanted this really super guy, but that got derailed by Obi-Wan. So he finds that, with Luke, he can get a more primo version if he can turn Luke to the Dark Side.”
This pretty clearly implies that Luke could become what Anakin was meant to be: a Force-user more powerful than Darth Maul, Count Dooku, or Darth Sidious. Luke is simply as “more primo” version of Anakin, unencumbered by loss of limbs or robotization. Anakin with the midi-chlorian levels he had in his youth, in other words.
This suggests that Luke was portrayed as having the same general level of power (and perhaps midi-chlorians) as Anakin: 20,000:
Qui-Gon took a slow, deep breath and exhaled softly. “What do the readings say, Obi-Wan?”
“They say the midi-chlorian count is twenty thousand.”
The Phantom Menace
However, one important caveat applies: now that Disney is in charge of canon, none of this may apply. That said, it seems that Disney is generally trying to keep their canon in line with what Lucas wrote, so these statements may be seen as having some canon validity. Further, some of the top people associated with the new canon, such as J.J. Abrams, have suggested that they don’t want to question Lucas’s pronouncements:
I will just say this: I would never presume to question anything George Lucas says is canon in Star Wars. And our job was not to negate or undo. A lot of people who are critics of our Star Trek, and I respect all of them, said we destroyed what they loved and negated everything. And we worked hard to clarify that we are not saying that our Star Trek over-rides a thing of the original Star Trek — it was a parallel timeline. I never wanted to negate canon that fans held so dear. And because I love Star Wars and have for too many years… … And having said all that and meaning it — I don’t want to presume over-write or change what George says the rules are.
Further, what is canon has showed Luke managed some pretty impressive feats, such as apparently deflecting an explosion using the Force (Shattered Empire):
And of course, the fact that Luke defeated Vader in lightsaber combat after giving into his anger is still quite canonical, giving us some evidence that he is stronger than Vader’s level of power as of the original trilogy.
I suppose, since all of the Jedi (or at least most of them) are dead and the order of the Jedi has been annihilated when Luke appears, the Jedi likely known as legends from the past, their knowledge and methods were lost as well. So, maybe no one is/was able to measure the midichlorians, if they are aware of them at all. I don't remember anyone talking about midichlorians in the original triology, but I don't know any extended Star Wars canon except some of the older video games.
Lucas said Luke is the most powerfull jedi or sith. So he should have the same count as his father. He reached his full potential.